FIG. 1 and FIG. 2 show a luminous module which has a light source substrate in the form of a printed circuit board 102 substantially shaped like a circular disk. The printed circuit board 102 is placed having its rear side 103 on a cooling body 104 used as the support and is equipped on its front side 105 with multiple light sources in the form of light-emitting diodes 106 and multiple electronic components 107. The luminous module 101 and the cooling body 104 can together form a luminous apparatus 101, 104 or can be part thereof.
The cooling body 104 has a substantially cylindrical basic shape. The light-emitting diodes 106 are arranged compactly in a central region 108 of the printed circuit board 102, and the electronic components 107 are located in a surrounding region 109 in the form of a circular ring, which concentrically encloses the central region 108.
A ring cover 110, which is open on the bottom side, covers or arches over, respectively, the surrounding region 109 of the printed circuit board 102. The ring cover 110 has an outer wall 111 having a substantially hollow-cylindrical shape and an inner wall 112 concentric thereto having a substantially hollow-cylindrical shape having smaller diameter. The outer wall 111 and the inner wall 112 are connected to one another by a horizontally level cover plate 113 or lid in the shape of a circular ring. In other words, the ring cover 110 has a cross-sectional shape which substantially corresponds to an inverted “U”. The ring cover 110 is seated on the printed circuit board 102, and so it is externally flush with the printed circuit board 102. The inner wall 112 encloses the light-emitting diodes 106 and is formed on its side facing toward the light-emitting diodes 106 as a mirrored or diffuse reflector, to form a light channel for the light-emitting diodes 106.
The ring cover 110 has a screw mount 114 to receive a screw 115 seated thereon, the screw 115 leading through a feedthrough opening 116 in the printed circuit board 102 into a screw hole 117 in the cooling body 104 and being screwed therein. By tightening the screw 115, the ring cover 110 is drawn toward the cooling body 104 and thus presses in the printed circuit board 102 to fix it between the ring cover 110 and the cooling body 104.
On an opposite side of the ring cover 110 with respect to an axis of symmetry S, this ring cover is held on the cooling body by means of an elastic bent sheet-metal strip 118 made of metal. The sheet-metal strip 118 is fastened by means of a screw 119 on the cooling body 104 and rests at its other end region on the cover plate 113 of the ring cover 110. The sheet-metal strip 118 is under tension, so that it presses the ring cover onto the printed circuit board 102 under all thermal load states, to suppress incorrect adaptations because of production tolerances, waste heat, and aging processes, etc.
The outer wall 111 protrudes forward beyond the cover plate 113, and does so over the entire circumference. The ring cover 110 thus has an upwardly directed projection 120 (which is formed by the region of the outer wall 111 protruding forward beyond the cover plate 113) even in a region in which the sheet-metal strip 118 arches over it. The sheet-metal strip 118 can thus be prevented from slipping off the ring cover 110 or vice versa.
Instead of the use of the sheet-metal strip 118, the ring cover can alternatively also be fastened by means of two or more screw mounts 114 and screws 115 received therein.